<?php
class PostUtil
{
	public function RemoveAllXSS($data)
	{
		if(!is_array($data))
		{
			return $this->RemoveXSS($data);
		}
		foreach($data as $k=>$v)
		{
			$data[$k]	= $this->RemoveAllXSS($v);
		}
		return $data;
	}
	
    public function RemoveXSS($val)
    {
	   // remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed   
	   // this prevents some character re-spacing such as <java\0script>   
	   // note that you have to handle splits with \n, \r, and \t later since they *are* allowed in some inputs   
	   $val = preg_replace('/([\x00-\x08][\x0b-\x0c][\x0e-\x20])/', '', $val);   
	      
	   // straight replacements, the user should never need these since they're normal characters   
	   // this prevents like <IMG SRC=&#X40&#X61&#X76&#X61&#X73&#X63&#X72&#X69&#X70&#X74&#X3A&#X61&#X6C&#X65&#X72&#X74&#X28&#X27&#X58&#X53&#X53&#X27&#X29>   
	   $search = 'abcdefghijklmnopqrstuvwxyz';   
	   $search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';   
	   $search .= '1234567890!@#$%^&*()';   
	   $search .= '~`";:?+/={}[]-_|\'\\';   
	   for ($i = 0; $i < strlen($search); $i++) {   
	      // ;? matches the ;, which is optional   
	      // 0{0,7} matches any padded zeros, which are optional and go up to 8 chars   
	      
	      // &#x0040 @ search for the hex values   
	      $val = preg_replace('/(&#[x|X]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;   
	      // &#00064 @ 0{0,7} matches '0' zero to seven times   
	      $val = preg_replace('/(&#0{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;   
	   }   
	      
	   // now the only remaining whitespace attacks are \t, \n, and \r   
	   $ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');   
	   $ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');   
	   $ra = array_merge($ra1, $ra2);   
	      
	   $found = true; // keep replacing as long as the previous round replaced something   
	   while ($found == true) {   
	      $val_before = $val;   
	      for ($i = 0; $i < sizeof($ra); $i++) {   
	         $pattern = '/';   
	         for ($j = 0; $j < strlen($ra[$i]); $j++) {   
	            if ($j > 0) {   
	               $pattern .= '(';   
	               $pattern .= '(&#[x|X]0{0,8}([9][a][b]);?)?';   
	               $pattern .= '|(&#0{0,8}([9][10][13]);?)?';   
	               $pattern .= ')?';   
	            }   
	            $pattern .= $ra[$i][$j];   
	         }   
	         $pattern .= '/i';   
	         $replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2); // add in <> to nerf the tag   
	         $val = preg_replace($pattern, $replacement, $val); // filter out the hex tags   
	      }  
	      if ($val_before == $val)
	      {   
            // no replacements were made, so exit the loop   
            $found = false;   
          }    
	   }
	   return $val;
	}  
}
?>